Commit Graph

45 Commits

Author SHA1 Message Date
Arnaldo Carvalho de Melo
31d68e7b66 perf annotate: Validate addr in symbol__inc_addr_samples
This routine was checking only if the provided address was after
sym->end, not if it was before sym->start.

Fix that by checking for both and return in both cases -ERANGE, so that
tools can communicate this to the user properly, or if they chose so, to
abort.

This problem was reported previously but the fixes involved either doing
what was being done for the > end case, i.e. silently drop the sample,
returning 0, or aborting at this function, which is in a lib (or better,
is slated to be at some point) and shouldn't abort.

The 'report' tool already checks this value and uses pr_debug to warn
the user.

This patch makes the 'top' tool check it too and warn once per map where
such range problem takes place.

Reported-by: David Miller <davem@davemloft.net>
Reported-by: Sorin Dumitru <dumitru.sorin87@gmail.com>
Reported-by: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-lw8gs7p9i9nhldilo82tzpne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-04-05 19:51:14 -03:00
Akihiro Nagai
0bc8d20580 perf script: Add option resolving vmlinux path
Add the option get the path of [kernel.kallsyms].
Specify '--show-kernel-path' option to use this function.
This patch enables other applications to use this output easily.

Without --show-kernel-path  option

ffffffff81467612 irq_return ([kernel.kallsyms])
ffffffff81467612 irq_return ([kernel.kallsyms])
    7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]

With --show-kernel-path option

ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
    7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120130044320.2384.73322.stgit@linux3
Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-01-30 18:13:07 -02:00
Akihiro Nagai
547a92e0ae perf script: Unify the expressions indicating "unknown"
The perf script command uses various expressions to indicate "unknown".

It is unfriendly for user scripts to parse it. So, this patch unifies
the expressions to "[unknown]".

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120130044257.2384.62905.stgit@linux3
Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-01-30 17:57:57 -02:00
Arnaldo Carvalho de Melo
b424eba271 perf session: Move threads to struct machine
The 'machine' abstraction was introduced with 'perf kvm' where we could
have samples for the host and multiple guests, but at the time we ended
up keeping the list of all machines threads all in
session->host_machine.

Move the threads rb_tree to struct machine to separate the namespaces.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mdg7sm6j3va09vtgj49gbsrp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-11-28 10:35:31 -02:00
David Ahern
e77b15bd84 perf tools: Add prelink suggestion to dso update message
Following a prelink run mapped files for long running processes can show
as deleted. The current message suggests restarting long running
processes. Add to that a suggestion that prelink might be the cause.

Old message:
/lib64/libc-2.14.so was updated, restart the long running
 apps that use it!

New message:
/lib64/libc-2.14.so was updated (is prelink enabled?).
  Restart the long running apps that use it!

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1318985085-20776-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-10-19 13:13:43 -02:00
Jiri Olsa
87ffef79ab perf symbols: Treat all memory maps without dso file as loaded
The stack/vdso/heap memory maps dont have any dso file.  Setting the
perf dso objects as 'loaded' for these maps, we avoid unnecessary
warnings like:

  "Failed to open [stack], continuing without symbols"

All map__find_* functions still return NULL when searching for symbols
in these maps.

Link: http://lkml.kernel.org/r/20110824131834.GA2007@jolsa.brq.redhat.com
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-09-29 17:10:48 -03:00
Arnaldo Carvalho de Melo
98dfd55d80 perf symbols: Stop using 'self' in map_groups__ methods
Stop using this python/OOP convention, doesn't really helps. Will do
more from time to time till we get it cleaned up in all of /perf.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-rl9e690y60vnuyng05yp1zd3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-09-29 16:41:36 -03:00
Arnaldo Carvalho de Melo
9486aa3877 perf tools: Fix 64 bit integer format strings
Using %L[uxd] has issues in some architectures, like on ppc64.  Fix it
by making our 64 bit integers typedefs of stdint.h types and using
PRI[ux]64 like, for instance, git does.

Reported by Denis Kirjanov that provided a patch for one case, I went
and changed all cases.

Reported-by: Denis Kirjanov <dkirjanov@kernel.org>
Tested-by: Denis Kirjanov <dkirjanov@kernel.org>
LKML-Reference: <20110120093246.GA8031@hera.kernel.org>
Cc: Denis Kirjanov <dkirjanov@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pingtian Han <phan@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-01-22 23:41:57 -02:00
Arnaldo Carvalho de Melo
0a1eae391d perf tools: Don't keep unreferenced maps when unmaps are detected
For a file with:

[root@emilia linux-2.6-tip]# perf report -D -fi allmodconfig-j32.perf.data | grep events:
     TOTAL events:      36933
      MMAP events:       9056
      LOST events:          0
      COMM events:       1702
      EXIT events:       1887
  THROTTLE events:          8
UNTHROTTLE events:          8
      FORK events:       1894
      READ events:          0
    SAMPLE events:      22378
      ATTR events:          0
EVENT_TYPE events:          0
TRACING_DATA events:          0
  BUILD_ID events:          0
[root@emilia linux-2.6-tip]#

Testing with valgrind and making perf_session__delete() a nop, so that
we can notice how many maps were actually deleted due to not having any
samples on it:

==== HEAP SUMMARY:

Before:

==10339==     in use at exit: 8,909,997 bytes in 68,690 blocks
==10339==   total heap usage: 78,696 allocs, 10,007 frees, 11,925,853 bytes allocated

After:

==10506==     in use at exit: 8,902,605 bytes in 68,606 blocks
==10506==   total heap usage: 78,696 allocs, 10,091 frees, 11,925,853 bytes allocated

I.e. just 84 detected unmaps with no hits out of 9056 for this workload,
not much, but in some other long running workload this may save more
bytes.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-02 19:45:23 -03:00
Arnaldo Carvalho de Melo
076c6e4521 perf session: Free the ref_reloc_sym memory at the right place
Which is at perf_session__destroy_kernel_maps, counterpart to the
perf_session__create_kernel_maps where the kmap structure is located, just
after the vmlinux_maps.

Make it also check if the kernel maps were actually created, which may not
be the case if, for instance, perf_session__new can't complete due to
permission problems in, for instance, a 'perf report' case, when a
segfault will take place, that is how this was noticed.

The problem was introduced in d65a458, thus post .35.

This also adds code to release guest machines as them are also created
in perf_session__create_kernel_maps, so should be deleted on this newly
introduced counterpart, perf_session__destroy_kernel_maps.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-02 18:18:28 -03:00
Arnaldo Carvalho de Melo
d65a458b34 perf tools: Release session and symbol resources on exit
So that we reduce the noise when looking for leaks using tools such as
valgrind.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-07-30 18:31:28 -03:00
Arnaldo Carvalho de Melo
591765fdaf perf tools: Release thread resources on PERF_RECORD_EXIT
For long running sessions with many threads with short lifetimes the
amount of memory that the buildid process takes is too much.

Since we don't have hist_entries that may be pointing to them, we can
just release the resources associated with each thread when the exit
(PERF_RECORD_EXIT) event is received.

For normal processing we need to annotate maps with hits, and thus
hist_entries pointing to it and drop the ones that had none. Will be
done in a followup patch.

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-07-30 18:28:42 -03:00
Dave Martin
361d134625 perf report: Don't abbreviate file paths relative to the cwd
This avoids around some problems where the full path is executables and DSOs it
needed for finding debug symbols on platforms with separated debug symbol files
such as Ubuntu.  This is simpler than tracking an extra name for each image.

The only impact should be that paths in verbose output from the perf tools
become absolute, instead of relative to .

LKML-Reference: <new-submission>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-07-27 11:39:04 -03:00
Arnaldo Carvalho de Melo
1f626bc368 perf session: Embed the host machine data on perf_session
We have just one host on a given session, and that is the most common
setup right now, so embed a ->host_machine struct machine instance
directly in the perf_session class, check if we're looking for it before
going to the rb_tree.

This also fixes a problem found when we try to process old perf.data
files where we didn't have MMAP events for the kernel and modules and
thus don't create the kernel maps, do it in event__preprocess_sample if
it wasn't already.

Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-05-09 21:14:52 -03:00
Arnaldo Carvalho de Melo
d28c62232e perf machine: Adopt some map_groups functions
Those functions operated on members now grouped in 'struct machine', so
move those methods to this new class.

The changes made to 'perf probe' shows that using this abstraction
inserting probes on guests almost got supported for free.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-27 21:21:18 -03:00
Arnaldo Carvalho de Melo
48ea8f5470 perf machine: Pass buffer size to machine__mmap_name
Don't blindly assume that the size of the buffer is enough, use
snprintf.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-27 21:19:05 -03:00
Arnaldo Carvalho de Melo
23346f21b2 perf tools: Rename "kernel_info" to "machine"
struct kernel_info and kerninfo__ are too vague, what they really
describe are machines, virtual ones or hosts.

There are more changes to introduce helpers to shorten function calls
and to make more clear what is really being done, but I left that for
subsequent patches.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-27 21:17:50 -03:00
Zhang, Yanmin
a1645ce12a perf: 'perf kvm' tool for monitoring guest performance from host
Here is the patch of userspace perf tool.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19 12:37:24 +03:00
Arnaldo Carvalho de Melo
7e5e1b1404 perf symbols: map_groups__find_symbol must return the map too
Tools need to know from which map in the map_group a symbol was resolved
to, so that, for isntance, we can annotate kernel modules symbols by
getting its precise name, etc.

Also add the _by_name variants for completeness.

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-02 16:27:43 -03:00
Arnaldo Carvalho de Melo
c6e718ff8c perf symbols: Move more map_groups methods to map.c
While writing a standalone test app that uses the symbol system to
find kernel space symbols I noticed these also need to be moved.

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-02 16:27:39 -03:00
Arnaldo Carvalho de Melo
4b8cf84624 perf symbols: Move map related routines to map.c
Thru series of refactorings functions were being renamed but not
moved to map.c to reduce patch noise, now lets have them in the
same place so that use of the symbol system by tools can be
constrained to building and linking fewer source files:
symbol.c, map.c and rbtree.c.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1269557941-15617-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-26 08:52:58 +01:00
Arnaldo Carvalho de Melo
b177f63f52 perf symbols: Pass the mmap parameters instead of using mmap_event
To reduce the coupling of the symbol system with the rest of
perf.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1269557941-15617-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-03-26 08:52:58 +01:00
Arnaldo Carvalho de Melo
3846df2e0a perf symbols: Improve debugging information about symtab origins
Be more clear about DSO long names and tell from which file
kernel symbols were obtained, all in --verbose mode:

    [root@mica ~]# perf report -v > /dev/null
    Looking at the vmlinux_path (5 entries long)
    Using /lib/modules/2.6.33-rc8-tip-00777-g0918527-dirty/build/vmlinux for symbols
    [root@mica ~]# mv /lib/modules/2.6.33-rc8-tip-00777-g0918527-dirty/build/vmlinux /tmp/dd
    [root@mica ~]# perf report -v > /dev/null
    Looking at the vmlinux_path (5 entries long)
    Using /proc/kallsyms for symbols
    [root@mica ~]#

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1266866139-6361-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 12:27:17 +01:00
Kirill Smelkov
ee11b90b12 perf top: Fix annotate for userspace
First, for programs and prelinked libraries, annotate code was
fooled by objdump output IPs (src->eip in the code) being
wrongly converted to absolute IPs. In such case there were no
conversion needed, but in

   src->eip = strtoull(src->line, NULL, 16);
   src->eip = map->unmap_ip(map, src->eip); // = eip + map->start - map->pgoff

we were reading absolute address from objdump (e.g. 8048604) and
then almost doubling it, because eip & map->start are
approximately close for small programs.

Needless to say, that later, in record_precise_ip() there was no
matching with real runtime IPs.

And second, like with `perf annotate` the problem with
non-prelinked *.so was that we were doing rip -> objdump address
conversion wrong.

Also, because unlike `perf annotate`, `perf top` code does
annotation based on absolute IPs for performance reasons(*), new
helper for mapping objdump addresse to IP is introduced.

(*) we get samples info in absolute IPs, and since we do lots of
    hit-testing on absolute IPs at runtime in record_precise_ip(), it's
    better to convert objdump addresses to IPs once and do no conversion
    at runtime.

I also had to fix how objdump output is parsed (with hardcoded
8/16 characters format, which was inappropriate for ET_DYN dsos
with small addresses like '4ac')

Also note, that not all objdump output lines has associtated
IPs, e.g. look at source lines here:

    000004ac <my_strlen>:
    extern "C"
    int my_strlen(const char *s)
     4ac:   55                      push   %ebp
     4ad:   89 e5                   mov    %esp,%ebp
     4af:   83 ec 10                sub    $0x10,%esp
    {
        int len = 0;
     4b2:   c7 45 fc 00 00 00 00    movl   $0x0,-0x4(%ebp)
     4b9:   eb 08                   jmp    4c3 <my_strlen+0x17>

        while (*s) {
            ++len;
     4bb:   83 45 fc 01             addl   $0x1,-0x4(%ebp)
            ++s;
     4bf:   83 45 08 01             addl   $0x1,0x8(%ebp)

So we mark them with eip=0, and ignore such lines in annotate
lookup code.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
[ Note: one hunk of this patch was applied by Mike in 57d8188 ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1265550376-12665-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-07 17:30:20 +01:00
Kirill Smelkov
7a2b620986 perf annotate: Fix it for non-prelinked *.so
The problem was we were incorrectly calculating objdump
addresses for sym->start and sym->end, look:

For simple ET_DYN type DSO (*.so) with one function, objdump -dS
output is something like this:

    000004ac <my_strlen>:
    int my_strlen(const char *s)
     4ac:   55                      push   %ebp
     4ad:   89 e5                   mov    %esp,%ebp
     4af:   83 ec 10                sub    $0x10,%esp
    {

i.e. we have relative-to-dso-mapping IPs (=RIP) there.

For ET_EXEC type and probably for prelinked libs as well (sorry
can't test - I don't use prelink) objdump outputs absolute IPs,
e.g.

    08048604 <zz_strlen>:
    extern "C"
    int zz_strlen(const char *s)
     8048604:       55                      push   %ebp
     8048605:       89 e5                   mov    %esp,%ebp
     8048607:       83 ec 10                sub    $0x10,%esp
    {

So, if sym->start is always relative to dso mapping(*), we'll
have to unmap it for ET_EXEC like cases, and leave as is for
ET_DYN cases.

(*) and it is - we've explicitely made it relative. Look for
    adjust_symbols handling in dso__load_sym()

Previously we were always unmapping sym->start and for ET_DYN
dsos resulting addresses were wrong, and so objdump output was
empty.

The end result was that perf annotate output for symbols from
non-prelinked *.so had always 0.00% percents only, which is
wrong.

To fix it, let's introduce a helper for converting rip to
objdump address, and also let's document what map_ip() and
unmap_ip() do -- I had to study sources for several hours to
understand it.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1265223128-11786-8-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04 09:33:27 +01:00